Triacylglycerol based wax composition

ABSTRACT

Wax compositions that have a high triacylglycerol content are provided. The wax compositions can be used to produce candle and are particularly useful in the production of container candles. The wax compositions commonly have a melting point of about 50° C. to 57° C. and include a triacylglycerol component, which has a fatty acid composition including about 14 to 25 wt. % 16:0 fatty acid.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation of U.S. application Ser. No.09/963,104, filed Sep. 25, 2001, now U.S. Pat. No. 7,128,766,incorporated herein by reference in its entirety.

BACKGROUND

Candles have been known and used for illumination since earlycivilization. The earliest candles are thought to have been developed bythe Egyptians who soaked the pithy cores of reeds in molten tallow andto make rushlights or torches. The Romans are credited with developingthe first candle which utilized a wick. The Romans also used tallow,derived from cattle or sheep suet, for candle wax. Around the middleages beeswax was found to be suitable in candles. Beeswax candles weredesirable over other candles because beeswax does not produce a smokyflame, or emit unpleasant odor when burned. Then, as now, beeswaxcandles were expensive, and prohibitively so, preventing most peoplefrom enjoying their advantages. Candles produced from molds firstappeared in 15^(th) century France.

In the American Northwest, Native Americans produced light by insertingoily candlefish (dried smelt) into the Y of a slit stick and lightingit. In a similar vein, the Stormy Petrel, and other birds having highfat content, were inserted with a wick and lit like candles.

America's first contribution to candlemaking occurred in colonial timeswhen it was discovered that the grayish-green berries of bayberry bushescould be boiled to produce a sweet-smelling wax that burned cleanly.Unfortunately, extracting wax from bayberries is extremely tedious andthe popularity of candles made from bayberry wax soon diminished.Candlemaking next benefited from the growth of the whaling industrybecause spermaceti, a wax obtained from the head of a sperm whale bycrystallizing the whale oil, became widely available. Spermaceti, likebeeswax, burned without an acrid odor and was also found to be harderthan either beeswax or tallow. This was advantageous because spermacetidid not soften or bend in the heat of summer.

The Industrial Revolution next shaped the production of candles byproviding machines which produced candles and paraffin wax, which isproduced by refining oil and coal shales. Paraffin, a bluish-white wax,burned cleanly with no unpleasant odor and was more economical toproduce than any previous candle fuel. Paraffin did have one drawback, alow melting point, which may have been a threat to its commercialviability if not for the introduction of stearic acid, a by-product ofanimal fat, into candles.

After the light bulb was introduced in the late nineteenth century theneed for candles diminished. A renewed popularity for candles emerged,especially for holidays and religious ceremonies, in the first half ofthe twentieth century. Much of this growth can be attributed to thegrowth of petrochemical refining and commercial meat production, whichproduce the two main constituents of present day candles—paraffin andstearic acid.

Recently environmental, health and supply concerns have sprung upconcerning the use of petroleum byproducts in candles. Candle waxformulations based upon natural materials, and in particular vegetableoils, have thus been proposed. However, the production of candles fromthese waxes has suffered several drawbacks, including cracking, airpocket formation, product shrinkage and a natural product odorassociated with vegetable materials. Various soybean-based waxes havebeen reported to suffer performance problems relating to optimum flamesize, effective wax and wick performance matching for an even burn,maximum burning time, failure to achieve a consistent appearance uponresolidification after melting, product color integration and/or productshelf life.

Additionally, there are several types of candles, including taper,votive, pillar, container candles and the like, each of which places itsown unique requirements on the wax used in the candle. For example,container candles, where the wax and wick are held in a container,typically glass, metal or the like, require lower melting points,specific burning characteristics such as wider melt pools, and shoulddesirably adhere to the container walls. The melted wax shouldpreferably retain a consistent appearance upon resolidification.

In order to achieve the aesthetic and functional product surface andquality sought by consumers of candles, it would be advantageous todevelop new waxes based on vegetable oil that overcome as many of thesedeficiencies as possible. Utilizing vegetable oil-based waxes would alsoprovide an additional outlet for agricultural production and has thepotential for reducing the cost of candle waxes due to a ready supply ofraw materials. Accordingly, it would be advantageous to have vegetablebased wax materials which can be used to form clean burning basematerials for forming candles. The candle base materials shouldpreferably have physical characteristics, e.g., in terms of meltingpoint, hardness and/or malleability, that permit the material to bereadily formed into container candles having a pleasing appearanceand/or feel to the touch, as well as having desirable olfactoryproperties.

SUMMARY

The present invention relates to wax compositions that have a hightriacylglycerol content, such as where a majority (i.e., at least about50 wt. %) of the wax is a triacylglycerol component. In some instances,essentially the entire wax fraction may be made up of triacylglycerolmaterial. The present waxes may suitably be chosen to have a meltingpoint of about 49° C. to 57° C. (120° F. to 135° F.). Where the wax isto be used to form a container candle, the wax commonly has a meltingpoint of about 50° C. to 57° C. (circa 122° F. to 135° F.) and, morecommonly, about 51° C. to 55° C. (circa 124° F. to 131° F.).

The triacylglycerol stock employed in the present wax compositionstypically has a fatty acid composition which includes about 14 wt. % to20 wt. % palmitic acid (16:0), about 20 wt. % to 30 wt. % stearic acid(18:0), and about 45 wt. % to 60 wt. % monounsaturated 18 carbon fattyacid (18:1). The triacylglycerol components used to produce the presentwax compositions can be provided by hydrogenating and/or blendingvegetable oils, such as soybean oil, palm oil and cottonseed oil.

The fatty acid composition of the triacylglycerol stock can also includesmall amounts of one or more additional fatty acids, such as up to about3 wt. % fatty acids having carbon chains of 14 atoms or less, no morethan about 3 wt. % linoleic acid, no more than about 1 wt. % linolenicacid and/or minor amounts, e.g. no more than about 3 wt. %, of fattyacids having 20 or more carbon atoms.

One embodiment of a triacylglycerol stock which can be used to producethe present wax can be formed by blending partially and/or fullyhydrogenated vegetable oils to produce a triacylglycerol compositionwith an Iodine Value of about 45 to 60 and the desired melting point,e.g., about 50° C. to 55° C. (122° F. to 131° F.). For example, atriacylglycerol stock can be formed by blending appropriate amounts ofpartially hydrogenated soybean oil and fully hydrogenated palm oil. Asused herein, the term “fully hydrogenated vegetable oil” refers to avegetable oil which has been hydrogenated to an Iodine Value of no morethan about 5. Suitable triacylglycerol stocks can also be formed bypartially hydrogenating a vegetable oil or a mixture of vegetable oilsto produce a triacylglycerol composition having a desired degree ofunsaturation, melting point and fatty acid composition. Instead ofemploying a highly hydrogenated vegetable oil, triacylglycerol materialderived from precipitating a hard fat fraction (i.e., a higher meltingpoint component of the material) from a vegetable oil may be employed.Hard fat fractions obtained in this manner are predominantly composed oftriacylglycerols which have saturated fatty acyl groups. Triacylglycerolstocks with high percentages of saturated fatty acids generally have ahigher melting point than corresponding triacylglycerol stocks withfatty acid compositions containing larger amounts of unsaturated fattyacids.

The present waxes have many applications including cosmetics and candlemanufacture, particularly into container candles. Depending on theparticular application, the present waxes may often include one or moreof a variety of other additives in addition to the triacylglycerolcomponent. Examples of such additives include colorants, fragrance oils,insect repellants, migration inhibitors, antioxidants and combinationsthereof. When present, fragrance oils are typically present in amountsfrom about 2 wt. % to 10 wt. % although the present waxes may includehigher amounts of fragrance oils, for example up to about 15 wt. % oreven higher. Migration inhibitors can comprise up to about 5 wt. % orhigher and customarily make up from about 0.1% to 2 wt. % of the wax.One type of suitable migration inhibitors are polymerization productsformed from one or more alpha olefins having about 10 to 25 carbonatoms. The present wax may also include other additives, e.g., aglycerol fatty acid monoester may be included in the wax blend. Theinclusion of a glycerol fatty acid monoester can enhance the enhance theability of colorants to be homogeneously distributed and maintainedthroughout the wax.

The present wax is typically solid, firm but not brittle, generallysomewhat malleable, has no free oil visible and is particularly good foruse in forming container candles. The present waxes are also capable ofproviding consistent characteristics, such as appearance, upon coolingand resolidification (e.g., after being burned in a candle) of themelted wax. The wax is desirably formulated to promote surface adhesionto prevent the candle from pulling away from the container when thecandle cools. In addition, it is desirable that the wax is capable ofbeing blended with natural color additives to provide an even, solidcolor distribution.

The present candles are typically formed from triacylglycerol-basedmaterial, e.g., vegetable oil-based material, which is a biodegradablematerial that can be produced from renewable resources. The candles aregenerally clean burning and emit very little soot. The combination oflow soot emission, biodegradability and production from renewable rawmaterial makes the present candle a particularly environmentallyfriendly product.

If the present wax is used to produce a candle, the same standard wicksthat are employed with other waxes (e.g., paraffin and/or beeswax) canbe utilized. In order to fully benefit from the environmentally-safeaspect of the present wax, it is desirable to use a wick which does nothave a metal core, such as a lead or zinc core. One example of asuitable wick material is a braided cotton wick.

A method of includes for making a candle using a wax which includes asubstantial triacylglycerol component is also provided. The methodincludes (a) heating the wax to a temperature above the melting point ofthe wax to form a hot liquefied wax; (b) cooling the hot liquefied waxto a pour temperature to form a cooled liquefied wax, where the pourtemperature is below the melting point of the wax and above the congealpoint of the wax; (c) pouring the cooled liquefied wax into a container;and (d) further cooling the cooled liquefied wax in the container to atemperature below the congeal point of the wax to form a candle. Themethod may also include adding a fragrance and/or colorant to the wax.The fragrance and/or colorant may be added to the cooled hot liquefiedwax prior to its introduction to the container or to the hot liquefiedwax. As used herein, the term “congeal point” refers to the temperatureat which a molten sample of a wax starts to form crystals. The “congealpoint” can be determined according to ASTM procedure ASTM D-938 and isused as an indication of the temperature at which the wax ceases toflow.

DETAILED DESCRIPTION

The physical properties of a triacylglycerol are primarily determined by(i) the chain length of the fatty acyl chains, (ii) the amount and type(cis or trans) of unsaturation present in the fatty acyl chains, and(iii) the distribution of the different fatty acyl chains among thetriacylglycerols that make up the fat or oil. Those fats with a highproportion of saturated fatty acids are typically solids at roomtemperature while triacylglycerols in which unsaturated fatty acylchains predominate tend to be liquid. Thus, hydrogenation of atriacylglycerol stock (“TAGS”) tends to reduce the degree ofunsaturation and increase the solid fat content and can be used toconvert a liquid oil into a semisolid or solid fat. Hydrogenation, ifincomplete, also tends to result in the isomerization of some of thedouble bonds in the fatty acyl chains from a cis to a transconfiguration. By altering the distribution of fatty acyl chains in thetriacylglycerol moieties of a fat or oil, e.g., by blending togethermaterials with different fatty acid profiles, changes in the melting,crystallization and fluidity characteristics of a triacylglycerol stockcan be achieved.

Herein, when reference is made to the term “triacylglycerol-basedmaterial” the intent is to refer to a material of which a majority ismade up of triacylglycerols. The present triacylglycerol-based materialtypically includes at least about 75 wt. % and may include about 90 wt.% or more triacylglycerol stock.

As employed herein, the terms “triacylglycerol stock” and“triacylglycerol component” are used interchangeably to refer tomaterials that are made up entirely of one or more triacylglycerolcompounds. Commonly, the triacylglycerol stock or triacylglycerolcomponent is a complex mixture of triacylglycerol compounds, which veryoften are derivatives of C16 and/or C18 fatty acids. The triacylglycerolstock, whether altered or not, is generally derived from various plantand/or animal sources, such as oil seed sources. The terms at leastinclude within their scope: (a) such materials which have not beenaltered after isolation; (b) materials which have been refined, bleachedand/or deodorized after isolation; (c) materials obtained by a processwhich includes fractionation of a triacylglycerol oil; and, also, (d)oils obtained from plant or animal sources and altered in some manner,for example through partial hydrogenation. Herein, the terms“triacylglycerols” and “triglycerides” are intended to beinterchangeable. It will be understood that a triacylglycerol stock mayinclude a mixture of triacylglycerols, and a mixture of triacylglycerolisomers. By the term “triacylglycerol isomers,” reference is meant totriacylglycerols which, although including the same esterifiedcarboxylic acid residues, may vary with respect to the location of theresidues in the triacylglycerol. For example, a triacylglycerol oil suchas a vegetable oil stock can include both symmetrical and unsymmetricalisomers of a triacylglycerol molecule which includes two different fattyacyl chains (e.g., includes both stearate and oleate groups).

As indicated above, any given triacylglycerol molecule includes glycerolesterified with three carboxylic acid molecules. Thus, eachtriacylglycerol includes three fatty acid residues. In general, oilsextracted from any given plant or animal source comprise a mixture oftriacylglycerols which is characteristic of the specific source. Themixture of fatty acids isolated from complete hydrolysis of thetriacylglycerols in a specific source is referred to herein as a “fattyacid composition” of the triacylglycerols. By the term “fatty acidcomposition” reference is made to the relative amounts of theidentifiable fatty acid residues in the various triacylglycerols. Thedistribution of specific identifiable fatty acids is characterizedherein by the amounts of the individual fatty acids as a weight percentof the total mixture of fatty acids obtained from hydrolysis of theparticular mixture of triacylglycerols. The distribution of fatty acidsin the triacylglycerols in a particular oil or fat may be readilydetermined by methods known to those skilled in the art, such as byhydrolysis, subsequent derivatization (e.g., to form a mixture of methylesters) and analysis by gas chromatography.

The total mixture of fatty acids in the present wax composition which isisolated after complete hydrolysis of any esters in a sample arereferred herein to as the “fatty acid profile” of that sample. Thus, the“fatty acid profile” of a sample includes not only the fatty acidsproduced by the hydrolysis of the triacylglycerols and/or other fattyacid esters but also any free fatty acids present in the sample. In manyinstances, the present wax is substantially free of any free fatty acid,e.g., the wax has a free fatty acid content of no more than about 0.5wt. %. As noted above, the distribution of fatty acids in a particularmixture may be readily determined by methods known to those skilled inthe art, e.g., via gas chromatography or conversion to a mixture offatty acid methyl esters followed by analysis by gas chromatography.

Palmitic acid (16:0) and stearic acid (18:0) are saturated fatty acidsand triacylglycerol acyl chains formed by the esterification of eitherof these acids do not contain any carbon-carbon double bonds. Thenomenclature in the above parentheses refers to the number of totalcarbon atoms in a straight chain fatty acid followed by the number ofcarbon-carbon double bonds in the chain. Many fatty acids such as oleicacid, linoleic acid and linolenic acid are unsaturated, i.e., containone or more carbon-carbon double bonds. Oleic acid is an 18 carbonstraight chain fatty acid with a single double bond (i.e., an 18:1 fattyacid), linoleic acid is an 18 carbon fatty acid with two double bonds orpoints of unsaturation (i.e., an 18:2 fatty acid), and linolenic is an18 carbon fatty acid with three double bonds (i.e., an 18:3 fatty acid).

The fatty acid composition of the triacylglycerol stock which makes up athe significant portion of the present wax composition generally is madeup predominantly of fatty acids having 16 or 18 carbon atoms. The amountof shorter chain fatty acids, i.e., fatty acids having 14 carbon atomsor less in the fatty acid profile of the triacylglycerols is generallyvery low, e.g., no more than about 3 wt. % and, more typically, no morethan about 1 wt. %. The triacylglycerol stock generally includes amoderate amount of saturated 16 carbon fatty acid, e.g., at least about14 wt. % and typically no more than about 25 wt. %, preferably fromabout 15 wt. % to 20 wt. %. As mentioned above, the fatty acidcomposition of the triacylglycerols commonly includes a significantamount of C18 fatty acid(s). In order to achieve a desirable containercandle characteristics, the fatty acids typically include a mixture ofsaturated 18 carbon fatty acid(s), e.g., about 20 wt. % to 30 wt. % and,more suitably, about 23 wt. % to 27 wt. % stearic acid, and 18 carbonunsaturated fatty acids, e.g., about 45 wt. % to 60 wt. % and moretypically about 50 wt. % to 57 wt. % 18:1 fatty acid(s), such as oleicacid. The unsaturated fatty acids are predominantly monounsaturatedfatty acid(s).

The fatty acid composition of the triacylglycerol stock is typicallyselected to provide a triacylglycerol-based material with a meltingpoint of about 49 to 57° C. When the present wax is to be used toproduce a container candle, the wax suitably is selected to have amelting point of about 51 to 55° C. The desired melting point can beachieve by altering several different parameters. The primary factorswhich influence the solid fat and melting point characteristics of atriacylglycerol are the chain length of the fatty acyl chains, theamount and type of unsaturation present in the fatty acyl chains, andthe distribution of the different fatty acyl chains within individualtriacylglycerol molecules. The present triacylglycerol-based materialsare formed from triacylglycerols with fatty acid profiles dominated byC18 fatty acids (fatty acids with 18 carbon atoms). Triacylglycerolswith extremely large amounts of saturated 18 carbon fatty acid (alsoreferred to as 18:0 fatty acid(s), e.g., stearic acid) tend to havemelting points which would be too high for the producing the presentcandles since such materials may be prone to brittleness, cracking andmay tend to pull away from the container into which the wax is poured.The melting point of such triacylglycerols can be lowered by blending intriacylglycerols with more shorter chain fatty acids and/or unsaturatedfatty acids. Since the present triacylglycerol-based materials havefatty acid profiles in which C18 fatty acids predominate, the desiredthe melting point and/or solid fat index is typically achieved byaltering the amount of unsaturated C18 fatty acids present(predominantly 18:1 fatty acid(s)).

Additionally, triacylglycerol based compositions which have fatty acidcompositions including a significant amount of saturated C16 fatty acidon the one hand, or diminutive amounts of saturated C16 fatty acid onthe other hand, can tend to exhibit undesirable physicalcharacteristics, and specifically are visually unpleasing due to theinconsistent crystallization of the wax upon cooling (such as occurs inrecooling of melted candle wax). Consistent characteristics and pleasingaesthetics in the recooled wax can be achieved by controlling the levelof saturated C16 fatty acid present in the fatty acid composition of thetriacylglycerol based materials used to produce the wax. In particular,it has been found that triacylglycerol-based waxes that have fatty acidcompositions which include about 14 to 25 wt. % palmitic acid (16:0fatty acid) generally tend to exhibit a much more consistent appearanceupon resolidification after melting than do similar wax compositionsderived entirely from soybean oil (soybean oil has a fatty acidcomposition which includes about 10 to 11 wt. % palmitic acid).

To enhance its physical properties, such as its capability of beingblended with natural color additives to provide an even solid colordistribution, in some instances the present wax may include a glycerolfatty acid monoester. Monoesters which are produced by partialesterification of a glycerol with a mixture of fatty acids derived fromhydrolysis of a triacylglycerol stock are suitable for use in thepresent wax compositions'. Examples include monoglycerol esters of amixture of fatty acids derived from hydrolysis of a partially or fullyhydrogenated vegetable oil, e.g., fatty acids derived from hydrolysis offully hydrogenated soybean oil. Where a glycerol fatty acid monoester isincluded in the present wax composition, it is generally present as arelatively minor amount of the total composition, e.g., the glycerolfatty acid monoester may constitute about 1 to 5 wt. % of the waxcomposition.

In some instances it may be advantageous to minimize the amount of freefatty acid(s) in the present wax. Since carboxylic acids can be somewhatcorrosive, the presence of fatty acid(s) in a candle wax can increaseits irritancy to skin. The presence of free fatty acid can alsoinfluence the olfactory properties of candles produced from the wax. Thepresent triacylglycerol-based wax can be used to produce candles and, inparticular, container candles, without the inclusion of free fattyacid(s) in the wax. Such embodiments of the presenttriacylglycerol-based wax suitably have a free fatty acid content(“FFA”) of less than about 1.0 wt. % and, preferably no more than about0.5 wt. %.

The composition(s) described herein can be used to provide candles fromtriacylglycerol-based materials having a melting point and/or solid fatcontent which imparts desirable molding and/or burning characteristics.The solid fat content, as determined at one or more temperatures, can beused as a measure of the fluidity properties of a triacylglycerol stock.The melting characteristics of the triacylglycerol-based material may becontrolled based on its solid fat index. The solid fat index is ameasurement of the solid content of a triacylglycerol material as afunction of temperature, generally determined at number of temperaturesover a range from 10° C. (50° F.) to 40° C. (104° F.). Solid fat content(“SFC”) can be determined by Differential Scanning calorimetry (“DSC”)using the methods well known to those skilled in the art. Fats withlower solid fat contents have a lower viscosity, i.e., are more fluid,than their counterparts with high solid fat contents.

The melting characteristics of the triacylglycerol-based material may becontrolled based on its solid fat index to provide a material withdesirable properties for forming a candle. Although the solid fat indexis generally determined by measurement of the solid content of atriacylglycerol material as a function over a range of 5 to 6temperatures, for simplicity triacylglycerol-based materials are oftencharacterized in terms of their solid fat contents at 10° C. (“SFI-10”)and/or 40° C. (“SFI-40”).

One measure for characterizing the average number of double bondspresent in a triacylglycerol stock which includes triacylglycerolmolecules with unsaturated fatty acid residues is its Iodine Value. TheIodine Value of a triacylglycerol or mixture of triacylglycerols isdetermined by the Wijs method (A.O.C.S. Cd 1-25) incorporated herein byreference. For example, soybean oil typically has an Iodine Value ofabout 125 to about 135 and a melting point of about 0° C. to about −10°C. Hydrogenation of soybean oil to reduce its Iodine Value to about 90increases the melting point of the material as evidenced by the increasein its melting point to about 10 to 20° C. Further hydrogenation canproduce a material which is a solid at room temperature and may have amelting point of 65° C. or even higher. Typically, the present candlesare formed from vegetable oil-based waxes which include atriacylglycerol stock having an Iodine Value of about 45 to about 60,and more suitably about 45 to about 55, and preferably about 50 to 55.The present waxes (including the triacylglycerol-based material andother components blended therewith) commonly have an Iodine Value ofabout 40-55 and, more suitably, about 45 to 55.

Feedstocks used to produce the triacylglycerol component in the presentcandle stock material have generally been neutralized and bleached. Thetriacylglycerol stock may have been processed in other ways prior touse, e.g., via fractionation, hydrogenation, refining, and/ordeodorizing. Preferably, the feedstock is a refined, bleachedtriacylglycerol stock. The processed feedstock material may be blendedwith one or more other triacylglycerol feedstocks to produce a materialhaving a desired distribution of fatty acids, in terms of carbon chainlength and degree of unsaturation. Typically, the triacylglycerolfeedstock material is hydrogenated to reduce the overall degree ofunsaturation in the material and provide a triacylglycerol materialhaving physical properties which are desirable for a candle-making basematerial.

Suitable hydrogenated vegetable oils for use in the presenttriacylglycerol-based material includes hydrogenated soybean oil,hydrogenated cottonseed oil, hydrogenated sunflower oil, hydrogenatedcanola oil, hydrogenated corn oil, hydrogenated olive oil, hydrogenatedpeanut oil, hydrogenated safflower oil or mixtures thereof. Thevegetable oil may be hydrogenated to obtain a desired set of physicalcharacteristics, e.g., in terms of melting point, solid fat contentand/or Iodine value. The hydrogenation is typically carried out atelevated temperature, such as about 205° C. to about 230° C. (400° F. to450° F.), and relatively low hydrogen pressure (e.g., no more than about25 psi) in the presence of a hydrogenation catalyst. One example of asuitable hydrogenation catalyst is a nickel catalyst, such as a powderednickel catalyst provided as a 20-30 wt. % suspension in a solidvegetable oil.

The present triacylglycerol stock can be produced by mixing a partiallyhydrogenated refined, bleached vegetable oil, such as a refined,bleached soybean oil which has been hydrogenated to an IV of about60-70, with a second oil seed-derived material having a higher meltingpoint, e.g., a fully hydrogenated palm oil. For example, this type ofpartially hydrogenated soybean oil can be blended with the fullyhydrogenated palm oil in a ratio which ranges from about 70:30 to 90:10,and more suitably about 75:25 to 85:15. As will be recognized by oneskilled in the art, these numbers are merely approximations and dependnot only upon the plant material from which the triacylglycerol stock isproduced but also the hydrogenation level of the triacylglycerol stock.The triacylglycerol stock produced thereby preferably has thecharacteristics described above and suitably has a melting point ofabout 50 to 57° C., an Iodine Value from about 40-55 and a 16:0 contentfrom about 15 to 18 wt. %. The triacylglycerol stock can be used aloneas a wax to form candles or additional wax materials can be added to thetriacylglycerol stock.

Although not preferred, the triacylglycerol component of the wax canalso be mixed with a minor amount of a free fatty acid component toachieve desired characteristics, such as melting point. When present,the free fatty acid is present in minimal amounts, preferably less thanabout 10 wt. % and more preferably no more than about 1 wt. %. The freefatty acid component is often derived from saponification of avegetable-oil based material and commonly includes a mixture of two ormore fatty acids. For example, the fatty acid component may suitablyinclude palmitic acid and/or stearic acid, e.g., where at least about 90wt. % of the fatty acid which makes up the fatty acid component ispalmitic acid, stearic acid or a mixture thereof. In general, the higherthe ratio of the hydrogenated oil to the fatty acid, the softer theproduct. A higher percentage of fatty acid generally produces a harderproduct. However, too high a level of a free fatty acid, such aspalmitic acid, in the wax can lead to cracking or breaking.

Not only do the present waxes include the triacylglycerol componentdescribed above, the present waxes can also include other waxes, such asbeeswax (which is primarily ceryl myristate), exotic plant waxes (e.g.,carnauba and/or bayberry wax), mineral waxes (e.g., montan wax) andpetroleum waxes (e.g., paraffin waxes). Although these additional waxescan be combined with the triacylglycerol component, the present waxespreferably include a majority of the triacylglycerol stock discussedabove. Preferably, the triacylglycerol portion makes up at least 75 wt.% and, commonly, at least 85 wt. % of the wax materials.

Although the triacylglycerol stock can be used for many application,including cosmetics, the triacylglycerol stock is well suited for use ascandle wax, particularly for container candles. The triacylglycerolstock of the present invention not only has the melting point andhardness desirable in container candle waxes, the presenttriacylglycerol wax also has the proper surface adhesion characteristicsso the wax does not pull away from the container when cooled.Additionally, the present triacylglycerol stock provides a consistent,even appearance when resolidified and does not exhibit undesirablemottling in the candle which results from uneven wax crystallization.

When the triacylglycerol stock is used in candle wax, thetriacylglycerol stock can further comprise one or more non-waxcomponents such as colorants, fragrance oils, insect repellants,migration inhibitors, antioxidants and color stabilizing additives. Thecolor stabilizing additives preferably absorb ultraviolet light toprevent colorant fading. A wide variety of coloring and scenting agents,well known in the art of candle making, are available for use with waxymaterials.

Typically, one or more dyes or pigments is employed provide the desiredhue to the color agent, and one or more perfumes, fragrances, essencesor other aromatic oils is used provide the desired odor to the scentingagent. The coloring and scenting agents generally also include liquidcarriers which vary depending upon the type of color- or scent-impartingingredient employed. The use of liquid organic carriers with coloringand scenting agents is particularly suitable because such carriers arecompatible with triacylglycerol-based waxes as well as petroleum-basedwaxes and related organic materials. As a result, such coloring andscenting agents tend to be readily absorbed into waxy materials. As aresult, coloring and/or scenting agent can often be introduced into thewaxy material when it is in the form of prilled granules.

The colorant is an optional ingredient and is commonly made up of one ormore pigments and/or dyes. Colorants are typically added in a quantityof about 0.001-2 wt. % of the waxy base composition. In the candlemakingart, pigments are generally solid color particles suspended, notdissolved, in wax and are used to coat the outside of the candle withcolor. Pigments are preferred when a solid wall of color, similar topaint, is desired. If a pigment is employed, it is typically an organictoner in the form of a fine powder suspended in a liquid medium, such asa mineral oil. It may be advantageous to use a pigment that is in theform of fine particles suspended in a vegetable oil, e.g., an naturaloil derived from an oilseed source such as soybean or corn oil. Thepigment is typically a finely ground, organic toner so that the wick ofa candle formed eventually from pigment-covered wax particles does notclog as the wax is burned.

Dyes, on the other hand, dissolve in the wax and are used to provide amore translucent color to the wax. Dyes are available in both liquid andpowder form, and if a dye constituent is utilized, it may be dissolvedin an organic solvent. A variety of pigments and dyes suitable forcandle making are listed in U.S. Pat. No. 4,614,625, the disclosure ofwhich is herein incorporated by reference. The preferred carriers foruse with organic dyes are organic solvents, such as relatively lowmolecular weight, aromatic hydrocarbon solvents; e.g. toluene andxylene. Since dyes tend to ionize in solution, they are more readilyabsorbed into the wax, whereas pigment-based coloring agents tend toremain closer to the surface of the wax.

Candles often are designed to appeal to the olfactory as well as thevisual sense. This type of candle usually incorporates a fragrance oilin the waxy body material. Fragrance oil is often added to the wax inamounts up to about 15 wt. % although amounts ranging from 3 to 8 wt. %are more common. As the waxy material is melted in a lighted candle,there is a release of the fragrance oil from the liquefied wax pool. Thescenting agent may be an air freshener, an insect repellent or serve oneor more of such functions.

The air freshener ingredient commonly is a liquid fragrance comprisingone or more volatile organic compounds which are available fromperfumery suppliers such IFF, Firmenich Inc., Takasago Inc., Belmay,Noville Inc., Quest Co., and Givaudan-Roure Corp. Most conventionalfragrance materials are volatile essential oils. The fragrance can be asynthetically formed material, or a naturally derived oil such as oil ofBergamot, Bitter Orange, Lemon, Mandarin, Caraway, Cedar Leaf, CloveLeaf, Cedar Wood, Geranium, Lavender, Orange, Origanum, Petitgrain,White Cedar, Patchouli, Lavandin, Neroli, Rose and the like.

A wide variety of chemicals are known for perfumery such as aldehydes,ketones, esters, alcohols, terpenes, and the like. A fragrance can berelatively simple in composition, or can be a complex mixture of naturaland synthetic chemical components. A typical scented oil can comprisewoody/earthy bases containing exotic constituents such as sandalwoodoil, civet, patchouli oil, and the like. A scented oil can have a lightfloral fragrance, such as rose extract or violet extract. Scented oilalso can be formulated to provide desirable fruity odors, such as lime,lemon or orange.

Synthetic types of fragrance compositions either alone or in combinationwith natural oils such as described in U.S. Pat. Nos. 4,314,915;4,411,829; and 4,434,306; incorporated herein by reference. Otherartificial liquid fragrances include geraniol, geranyl acetate, eugenol,isoeugenol, linalool, linalyl acetate, phenethyl alcohol, methyl ethylketone, methylionone, isobornyl acetate, and the like. The scentingagent can also be a liquid formulation containing an insect repellentsuch as citronellal or neem oil, or a therapeutic agent such aseucalyptus or menthol. Once the coloring and scenting agents have beenformulated, the desired quantities are combined with waxy material whichwill be used to form the body of the candle. For example, the coloringand/or scenting agents can be added to the waxy materials in the form ofprilled wax granules. When both coloring and scenting agents areemployed, it is generally preferable to combine the agents together andthen add the resulting mixture to the wax. It is also possible, however,to add the agents separately to the waxy material. Having added theagent or agents to the wax, the granules are coated by agitating the waxparticles and the coloring and/or scenting agents together. Theagitating step commonly consists of tumbling and/or rubbing theparticles and agent(s) together. Preferably, the agent or agents aredistributed substantially uniformly among the particles of wax, althoughit is entirely possible, if desired, to have a more random pattern ofdistribution. The coating step may be accomplished by hand, or with theaid of mechanical tumblers and agitators when relatively largequantities of prilled wax are being colored and/or scented.

Certain additives may be included in the present wax compositions todecrease the tendency of colorants, fragrance components and/or othercomponents of the wax to migrate to an outer surface of a candle. Suchadditives are referred to herein as “migration inhibitors.” The wax mayinclude about 0.1 to 5.0 wt. % and, more typically, about 0.5 to 2.0 wt.% of a migration inhibitor. One type of compounds which can act asmigration inhibitors are polymerized alpha olefins, more particularlypolymerization products formed alpha olefins having at least 10 carbonatoms and, more commonly from one or more alpha olefins having 10 toabout 25 carbon atoms. One suitable example of such as polymer is analpha olefin polymer sold under the tradename Vybar® 103 polymer (mp168° F. (circa 76° C.); available from Baker-Petrolite, Sugarland,Tex.). The inclusion of sorbitan triesters, such as sorbitan tristearateand/or sorbitan tripalmitate and related sorbitan triesters formed frommixtures of fully hydrogenated fatty acids, in the present waxcompositions may also decrease the propensity of colorants, fragrancecomponents and/or other components of the wax to migrate to the candlesurface. The inclusion of either of these types of migration inhibitorscan also enhance the flexibility of the base wax material and decreaseits chances of cracking during the cooling processes that occur incandle formation and after extinguishing the flame of a burning candle.For example, it may be advantageous to include up to about 5.0 wt. %and, more commonly, about 0.1-2.0 wt. % of a migration inhibitor, suchas an alpha olefin polymer, in the present wax materials.

Additionally, because the present waxes can contain components whichinclude some degree of unsaturated fatty acids, the present waxes maycontain antioxidants. Numerous examples of antioxidants are known.Although many antioxidants are suitable for use as present lipid solubleantioxidants are preferred. Antioxidants found in natural sources, suchas tocopherols (i.e., alpha tocopherol), carotenoids, and flavonoids,are suitable. Other suitable antioxidants include t-butylhyrdoquinone(TBHQ) or butylated hydroxytoluene (BHT).

Surprisingly and unexpectedly it has been discovered that the candleswith excellent performance properties can be produced by heating atriacylglycerol based wax to a temperature above the melting point ofthe wax to form a hot liquefied wax, cooling the hot liquefied wax to atemperature to a pour temperature below the melting point of the wax butabove the congeal point of the wax to form a cool liquefied wax,introducing the cooled liquefied wax into a designated container andsubsequently cooling the wax in the container to a temperature below itscongeal point, thereby solidifying the wax. Preferably, the hotliquefied wax is cooled to about 10 to 15° C. below the melting point ofthe wax to provide the cool liquefied wax. As stated above, the waxescan include several optional ingredients. When colorants are used theyare preferably added to the hot liquefied wax due to their stability.Alternatively, the colorant can be added at almost any stage of theprocess, and, indeed, the wax can be previously colored wax can be usedin the present method. As most fragrances are volatile, it commonly ispreferable to add fragrance oil(s) to the wax at as low a temperature aspossible as is practicable, such as adding the fragrance to the coolliquefied wax at its pour temperature. However, as the temperaturesrequired to melt triacylglycerol based waxes are not as high as thoserequired for conventional waxes, fragrance can be added earlier in theprocess, such as to the hot liquefied wax, and the fragrance can even beincorporated into the wax even prior to the candle forming method.Generally, this method is not well suited to wax compositions whichcontain migration inhibitors because the migration inhibitors tend toincrease the congeal point of the wax to about the same temperature asthe melting point of the wax.

Typically, the candle wick is anchored in the middle of the bottom endof the container in which the wax is poured. The wick may also beinserted into either the hot liquefied wax, the cool liquefied wax orinto the solidified wax. Candle wicks usable in the present candlesinclude standard wicks used for conventional candles. Such wicks can bemade of braided cotton and may have a metal or paper core. Because mostcontainer candles tend to have relatively large widths, larger wicks arepreferred to provide an ideal melt pool.

The present method for producing candles is advantageous in thattriacylglycerol based candles formed according to this method canprovide one-pour convenience so that second, and subsequent pours of thewax are not necessarily required to fill in a depression left as the waxcools.

Candles can be produced from the triacylglycerol-based material using anumber of other methods. In one common process, the vegetable oil-basedwax is heated to a molten state. If other additives such as colorantsand/or fragrance oils are to be included in the candle formulation,these may be added to the molten wax or mixed with vegetable oil-basedwax prior to heating. The molten wax is then commonly solidified arounda wick. For example, the molten wax can be poured into a mold whichincludes a wick disposed therein. The molten wax is then cooled to thesolidify the wax in the shape of the mold. Depending on the type ofcandle being produced, the candle may be unmolded or used as a candlewhile still in the mold.

The candle wax may be fashioned into a variety of forms, commonlyranging in size from powdered or ground wax particles approximatelyone-tenth of a millimeter in length or diameter to chips, flakes orother pieces of wax approximately two centimeters in length or diameter.Where designed for use in compression molding of candles, the waxyparticles are generally spherical, prilled granules having an averagemean diameter no greater than about one (1) millimeter.

Prilled waxy particles may be formed conventionally, by first melting atriacylglycerol-based material, in a vat or similar vessel and thenspraying the molten waxy material through a nozzle into a coolingchamber. The finely dispersed liquid solidifies as it falls through therelatively cooler air in the chamber and forms the prilled granulesthat, to the naked eye, appear to be spheroids about the size of grainsof sand. Once formed, the prilled triacylglycerol-based material can bedeposited in a container and, optionally, combined with the coloringagent and/or scenting agent.

Kits for forming articles (e.g., candles) from the presenttriacylglycerol wax are also provided by the present application. Thesekits can include one or more of the directions for forming candles fromthe present invention described above and a quantity of the presenttriacylglycerol-based wax, as well as a colorant, fragrance, wickmaterial, molds and other additives discussed herein. Another kitembodied in the present invention provides instructions for carrying outthe candle making method described herein and may also include any ofthe previously mentioned additional candle components.

The following examples are presented to illustrate the present inventionand to assist one of ordinary skill in making and using the same. Theexamples are not intended in any way to otherwise limit the scope of theinvention.

EXAMPLE 1

A vegetable oil-based wax suitable for use in making candles wasproduced according to the following procedure. A partially hydrogenatedrefined, bleached soybean oil (about 85 parts by weight) and a fullyhydrogenated palm oil (about 15 parts by weight) were heated to about140° F. (circa 60° C.) and stirred to thoroughly blend the components toform a homogenous mixture. The partially hydrogenated refined, bleachedsoybean oil had a melting point of about 112-115° F. (circa 44-46° C.)and an Iodine Value of about 60-64. The resulting blend had a meltingpoint of about 126° F. (circa 52° C.), an Iodine Value of 54 and wassuitable for use in a container candle.

The fatty acid composition of the resulting blend is shown in Table 1below. The fatty acid compositions of the partially hydrogenated refinedand bleached soybean oil (“PH-SBO”) and a fully hydrogenated palm oil(“FH-Palm”) are also shown for comparison.

TABLE 1 Fatty Acid Compositions (Wt. %) Fatty Acid(s) PH-SBO FH-Palm85/15 Blend ≦ C14 <0.3 1-2 0.4 16:0 10.4 42-44 14.9 18:0 18.3 53-55 23.718:1 66.8 — 56.8 18:2 2.9 — 2.5 18:3 0.1 — — Other 1.0 — 0.5

The final candle formulation may be used to directly produce candles ormay be stored in a molten state in a heated tank. Often it may be moreconvenient to convert the candle wax into particle form. As describedabove, the molten candle wax may be converted into flakes or prilledgranules to facilitate handling and storage in small lots.

EXAMPLE 2

A vegetable oil-based wax suitable for use in making candles wasproduced according to the procedure described in Example 1 from thepartially hydrogenated refined, bleached soybean oil (about 80 parts byweight) and fully hydrogenated palm oil (about 20 parts by weight). Theresulting blend had a melting point of about 128° F. (circa 53° C.), anIodine Value of 50 and was suitable for use in producing a containercandle. The fatty acid composition of the resulting blend is shown inTable 2 below. The fatty acid composition of a typical refined andbleached soybean oil (“RB-SBO”) is also shown for comparison.

TABLE 2 Fatty Acid Compositions (Wt. %) Fatty Acid(s) RB-SBO 80/20 Blend≦ C14 <0.1 ≦0.4 16:0 10-11 16 18:0 4-6 27.6 18:1 20-30 52.8 18:2 50-602.5 18:3  5-10 — Other <1   0.7

EXAMPLE 3

A container candle was produced using the wax prepared according toExample 2. The vegetable oil-based wax of Example 2 (94 parts by weight)was heated to about 140° F. (circa 60° C.). Candle jasmine fragrance oil(6 parts by weight; French Color & Chemical Co., Englewood, N.J.) and ablue liquid dye (parts by weight; available from French Color & ChemicalCo., Englewood, N.J. under the product number D-878 French Color &Chemical Co., Englewood, N.J.) were blended into the molten vegetableoil-based wax. The resulting blend was cooled to about 115° F. (circa46° C.) and then poured into a 10.5 oz, 3 inch diameter glass containercontaining a paper core cotton wick (available from Wicks Unlimited,Cutchogue, N.Y. under the product number 60-44-18P). The molten wax wasallowed to cool to room temperature and the resulting container candlewas used in the burn test described below.

The wick in the candle formed from the wax of Example 2 was lit and thecandle was allowed to burn for 4 hours. During the burn test the flamereached a maximum flame height of 30 mm. The melt pool formed during theburn test reached all the way out to the edges of the container andachieved a maximum depth of ¼ inch. The melt pool reached a maximumtemperature of 160° F. (circa 71° C.) during the duration of the burn.The wax had a disappearance rate of 4.6 g/hr during the burn test (basedon the total weight loss of the candle over the 4 hour burn period). Nosooting was noted during the duration of the burn test. Upon cooling thewax solidified to form a smooth surface with little or no marring. Thetime required for the wax to resolidify with the candle exposed toambient temperature was about 20 minutes.

For comparison purposes, a commercial container candle formed fromparaffin wax was lit and the candle was allowed to burn for 4 hours.During the burn test the flame reached a maximum flame height of about40 mm. The melt pool formed during the burn test reached all the way outto the edges of the container and achieved a maximum depth of about ½inch. The melt pool reached a maximum temperature of 155° F. (circa 68°C.) during the duration of the burn. Sooting was observed during theduration of the burn test and some deposition of soot on the inside ofthe container was observed. Upon cooling the paraffin wax solidified toform a smooth surface with little or no marring. The time required forthe wax to resolidify with the candle exposed to ambient temperature wasabout 15 minutes.

All percentages discussed herein are percentages by weight unlessotherwise specified.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges and subranges described herein also encompass any and allpossible combinations of ranges, subranges and/or specific valuesdisclosed herein. As will also be understood by one skilled in the art,all language such as “up to”, “at least”, “greater than”, “no morethan”, “less than” and the like refer to threshold values which can beused to define boundaries of ranges and/or subranges as discussed above.

The present invention has been described with reference to variousspecific and illustrative embodiments and techniques. However, it shouldbe understood that many variations and modifications may be made whileremaining within the spirit and scope of the invention.

1. A candle comprising a wick and wax; wherein the wax has a meltingpoint of about 49° C. to 57° C.; and Iodine Value of about 40 to 63; andcomprises a triacylglycerol component, which has a fatty acidcomposition including about 14 to 25 wt. % saturated 16 carbon fattyacid.
 2. The candle of claim 1 wherein the triacylglycerol component hasan Iodine Value of about 45 to about
 60. 3. The candle of claim 1wherein the wax has an Iodine Value of about 45 to about
 55. 4. Thecandle of claim 1 wherein the wax comprises at least about 75 wt. % ofthe triacylglycerol component.
 5. The candle of claim 1 furthercomprising a migration inhibitor.
 6. The candle of claim 5 wherein themigration inhibitor comprises an alpha-olefin polymer.
 7. The candle ofclaim 1 further comprising fragrance oil.
 8. The candle of claim 1consisting essentially of the triacylglycerol component.
 9. The candleof claim 1 wherein the fatty acid composition comprises about 20 to 30wt. % 18:0 fatty acid.
 10. The candle of claim 1 further comprising anadditional wax selected from the group consisting of beeswax, paraffinwax, microcrystalline wax, carnauba wax, bayberry wax, montan wax andcombinations thereof.
 11. The candle of claim 10 comprising no more thanabout 15 wt. % of the additional wax.
 12. The candle of claim 1 furthercomprising petroleum wax.
 13. The candle of claim 12 wherein thepetroleum wax comprises paraffin wax, microcrystalline wax, or a mixturethereof.
 14. The candle of claim 1 wherein the fatty acid compositionincludes no more than about 50 wt. % saturated fatty acids.
 15. Thecandle of claim 1 wherein the wax has a free fatty acid content of nomore than about 0.5 wt. %.
 16. The candle of claim 1 wherein the fattyacid composition includes about 45 to 60 wt. % 18:1 fatty acid.
 17. Thecandle of claim 1 wherein the wax comprises at least about 90 wt. % ofthe triacylglycerol component.
 18. The candle of claim 17 wherein thewax comprises hydrogenated vegetable oil.
 19. The candle of claim 18wherein the hydrogenated vegetable oil comprises hydrogenated soybeanoil.
 20. The candle of claim 18 wherein the hydrogenated vegetable oilcomprises hydrogenated palm oil.
 21. The candle of claim 18 wherein thehydrogenated vegetable oil comprises hydrogenated cottonseed oil. 22.The candle of claim 18 wherein the hydrogenated vegetable oil compriseshydrogenated corn oil, hydrogenated corn oil, hydrogenated cottonseedoil, hydrogenated palm oil, hydrogenated soybean oil, hydrogenated palmoil, hydrogenated peanut oil, hydrogenated safflower oil, hydrogenatedsunflower oil, or a mixture thereof.
 23. The candle of claim 1 whereinthe fatty acid composition includes no more than about 3 wt. % fattyacids having 14 or less carbon atoms.
 24. The candle of claim 1 whereinthe wax consists essentially of a blend of partially hydrogenatedsoybean oil having an Iodine Value of about 60 to 70; and fullhydrogenated palm oil.
 25. The candle of claim 1 wherein the wax furthercomprises glycerol fatty acid monoester.
 26. The candle of claim 25wherein the wax comprises about 1 to 5 wt. % of the glycerol fatty acidmonoester.
 27. The candle of claim 1 wherein the wax further comprisessorbitan fatty acid triester.
 28. The candle of claim 1, wherein the waxconsists essentially of hydrogenated soybean oil and hydrogenated palmoil in a weight ratio of about 70:30 to 90:10.
 29. The candle of claim28, wherein the wax has an Iodine Value of about 42 to
 63. 30. A candlecomprising a wick and wax; wherein the wax has a melting point of about49° C. to 57° C.; and consists essentially of a triacylglycerolcomponent, which has a fatty acid composition including about 14 to 25wt. % saturated 16 carbon fatty acid.
 31. A candle comprising a wick andwax; wherein the wax has a melting point of about 49° C. to 57° C.; andcomprises a triacylglycerol component, which has a fatty acidcomposition including about 14 to 25 wt. % 16:0 fatty acid and about 45to 60 wt. % 18:1 fatty acid.
 32. The candle of claim 31 wherein the waxcomprises at least about 90 wt. % of the triacylglycerol component.